(1) Field of the Invention
The present invention generally relates to a projector, and particularly relates to a projector for reducing a temperature of a light source.
(2) Description of the Prior Art
Please refer to FIG. 1A, which is illustrating a conventional projector 2. The conventional projector 2 comprises a light source 4, an Ultraviolet/Infrared Radiation (UV/IR) filter 6, a color wheel 8, an integration rod 10, a light valve 12, and a projection lens 14.
Please refer to FIG. 1B, which is illustrating a light path of the conventional projector according to FIG. 1A. The light source 4 comprises a lamp 402 for providing a light beam and a lamp reflector 404. The lamp reflector 404 guides the light beam toward the UV/IR filter 6. The UV/IR filter 6 transmits a visible light beam of the light beam and reflects an ultraviolet (UV) and an infrared radiation (IR) of the light beam.
The visible light beam-passes through the UV/IR filter 6 and the color wheel 8. The color wheel 8 comprises different filters for several primary colors, such as red, green and blue. While the color wheel 8 rotates, a primary color light beam of the light beam passes through the color wheel 8 in a predetermined time section, and the other color light beam of the light beam is reflected by the color wheel 8.
Following, the primary color light beam passing through the color wheel 8 passes through the integration rod 10 for uniforming the light beam to project on the light valve 12. After modulated by the light valve 12, the primary color light beam passes through the projection lens 14 to display images on a screen.
A weighty issue of the projector is a heat from the light source 4. The UV and IR reflected from the UV/IR filter 6, and the visible light beam reflected from the color wheel 8 are reflected back to the light source 4 so as to raise a temperature of the light source 4. This high temperature causes a damage on the light source 4 and harms the display performance of the projector 2.